25506992421 has 24 divisors (see below), whose sum is σ = 38220122304. Its totient is φ = 16999269120.

The previous prime is 25506992411. The next prime is 25506992429. The reversal of 25506992421 is 12429960552.

25506992421 is a `hidden beast` number, since 2 + 550 + 6 + 9 + 92 + 4 + 2 + 1 = 666.

It is not a de Polignac number, because 25506992421 - 2³¹ = 23359508773 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25506992429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 842181 + ... + 871941.

It is an arithmetic number, because the mean of its divisors is an integer number (1592505096).

Almost surely, 2^25506992421 is an apocalyptic number.

It is an amenable number.

25506992421 is a deficient number, since it is larger than the sum of its proper divisors (12713129883).

25506992421 is an equidigital number, since it uses as much as digits as its factorization.

25506992421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33303 (or 33291 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 25506992421 in words is "twenty-five billion, five hundred six million, nine hundred ninety-two thousand, four hundred twenty-one".